About Pediatric Hemophagocytic Lymphohistiocytosis

Brayton was diagnosed with hemophagocytic lymphohistiocytosis (HLH) when he was 4 months old.

Hemophagocytic Lymphohistiocytosis (or “HLH”) is a blood and immune system disorder that mainly affects infants and young children, but can occur at any age. HLH occurs when histiocytes and lymphocytes (two kinds of white blood cells that fight infection) cause the immune system to overreact and attack healthy tissue and organs, most often the bone marrow, liver and brain.

Hemophagocytic lymphohistiocytosis is very rare and its cause is still unknown. In many childhood cases, genetics play a role, but HLH can also result from infections, immune system diseases and cancer.

Our renowned hematologists, oncologists and researchers at the Nemours Center for Cancer and Blood Disorders work together to quickly and accurately diagnose and treat hemophagocytic lymphohistiocytosis and other immune system diseases in infants and children, including primary (also called “familial”) and secondary (also called “acquired”) forms of this disease.

Types of Childhood Hemophagocytic Lymphohistiocytosis We Treat

Primary Hemophagocytic Lymphohistiocytosis

Primary or familial hemophagocytic lymphohistiocytosis is an inherited immune system disease, which means it inhibits the body's natural defense system. Primary HLH represents 25 percent of the cases and is most often diagnosed in infants within the first 12 months of life (although there are cases of children being diagnosed much older).

Secondary Hemophagocytic Lymphohistiocytosis

Secondary (or “acquired/reactive”) hemophagocytic lymphohistiocytosis is associated with certain viruses, complications from juvenile idiopathic arthritis, rheumatologic disorders and cancer, and is diagnosed most often in childhood.

Diagnosis

Diagnosing Hemophagocytic Lymphohistiocytosis in Children

Signs & Symptoms of Hemophagocytic Lymphohistiocytosis

Like most immune system diseases, symptoms of hemophagocytic lymphohistiocytosis in children vary, but can include:

persistent fever

rash

enlarged or inflamed liver and/or spleen

jaundice (yellowing of the skin and eyes)

difficulty breathing

digestive problems

Central nervous system symptoms such as seizures, weakness, vision problems and headaches can also occur. It’s important to diagnose pediatric HLH early and begin treatment right away for the best outcome.

Testing & Evaluations

If your child possibly has pediatric hemophagocytic lymphohistiocytosis, Nemours’ experienced hematology and oncology care team works together to appropriately and quickly diagnose and stage the immune system disease through a variety of tests and procedures, including:

thorough physical examination and medical history

blood tests

bone marrow aspiration and biopsy

Treatment

Treating & Caring for Children With Hemophagocytic Lymphohistiocytosis

Your Child's Comprehensive Pediatric Hematology Care Team

If we discover hemophagocytic lymphohistiocytosis or other immune system diseases, our multidisciplinary (collaborative) team plans the most effective treatment personalized to your child’s needs.

Your care team is here to provide your family with ongoing support and follow-up. We always include you in the entire process, because we truly believe in the healing power of families and that you know your child best.

Treating pediatric hemophagocytic lymphohistiocytosis and other immune system diseases varies depending on the type, severity, your child’s age and overall health. Secondary (or “acquired”) HLH can sometimes resolve when the underlying condition causing it is treated, but that’s not always the case. Primary (or “familial”) HLH must be treated quickly.

Hemophagocytic lymphohistiocytosis can include one or more of the following:

Additional Resources & Support for Families

Nemours Support Services

Dealing with a complex medical condition is difficult for your child and family. But you don’t have to go through it alone. Nemours provides an array of support services that begin on the very first day we meet, and continues throughout your journey because at Nemours, your child and family become part of our own.

Treatments

Histiocytosis Association: This global nonprofit organization dedicated to addressing the unique needs of patients and families dealing with the effects of histiocytic disorders such as hemophagocytic lymphohistiocytosis while leading the search for a cure.

National Bone Marrow Transplant Link: The organization helps patients, caregivers and families cope with the social and emotional challenges of bone marrow/stem cell transplantation, from diagnosis through survivorship. They provide information and personalized support services.